The present invention relates to semiconductor devices and more particularly to technology for a semiconductor device having a bipolar transistor.
In making an electric circuit in a semiconductor substrate, a bipolar transistor may be provided in the semiconductor substrate. For example, Japanese Unexamined Patent Application Publications Nos. Hei 5(1993)-90278, 2005-236084, and 2011-119344 describe that a bipolar transistor is formed by stacking an impurity layer to become an emitter, an impurity layer to become a base, and an impurity layer to become a collector in the thickness direction of the semiconductor substrate.
In recent years, in order to miniaturize a FET (Field Effect Transistor), a fin-type semiconductor layer is used in the FET forming process (for example, see Japanese Unexamined Patent Application Publications No. 2007-165780 and Japanese Translation of PCT International Application Publication No. JP-T-2013-511852).